memiliki sifat yang berlawanan; sanggup bertindak sebagai asam ataupun basa; bergabung dengan asam maupun basa; memengaruhi lakmus merah maupun biru.

Merriam-Webster Online Dictionary
amphoteric (adjective)
partly one and partly the other , specifically capable of reacting chemically either as an acid or as a base
amphoteric (Wikipedia)

In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid as well as a base. Many metals (such as copper, zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation states of the oxide. Al2O3 is an amphoteric oxide

Metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides. Amphoteric oxides include lead oxide and zinc oxide, among many others.

One type of amphoteric species are amphiprotic molecules, which can either donate or accept a proton (H+). Examples include amino acids and proteins, which have amine and carboxylic acid groups, and self-ionizable compounds such as water.

Ampholytes are amphoteric molecules that contain both acidic and basic groups and will exist mostly as zwitterions in a certain range of pH. The pH at which the average charge is zero is known as the molecule's isoelectric point.

Ampholytes are used to establish a stable pH gradient for use in isoelectric focusing.